v1.6.0 to use new ESP8266 core v3.0.0

### Major Releases v1.6.0

1. Fix AP connect issue caused by **breaking ESP8266 core v3.0.0**. Caused by multiple core changes, but the new solution results a better and faster connection to AP.
2. Fix SSL issue caused by breaking ESP8266 core v3.0.0. Now the better **BearSSL** is used in both ESP32 and ESP8266 to replace the ESP8266 deprecated `axTLS`. Check [Remove axTLS from code and documentation #7437](esp8266/Arduino#7437)
3. Fix the `BLYNK_INFO_DEVICE`displaying the generic ESP8266 board with Blynk logo. Caused by new ESP8266 core changes of `build.board`. For example from `ESP8266_NODEMCU` in core v2.7.4 to `ESP8266_NODEMCU_ESP12E` in core v3.0.0
4. Fix many warnings only displayed in new core ESP8266 v3.0.0
5. Make code compatible for either new ESP8266 core v3.0.0+ or ealier cores v2.7.4-

Author: khoih-prog

README.md

@@ -18,6 +18,7 @@
   * [Features](#features)
   * [Currently supported Boards](#currently-supported-boards)
 * [Changelog](#changelog)
+  * [Major Releases v1.6.0](#major-releases-v160)
   * [Releases v1.5.0](#releases-v150)
   * [Major Releases v1.4.0](#major-releases-v140)
   * [Releases v1.3.1](#releases-v131)
@@ -126,6 +127,7 @@
   * [9. ESP32WM_MRD_ForcedConfig using LITTLEFS with SSL on ESP32_DEV to demo WiFi Scan](#9-esp32wm_mrd_forcedconfig-using-littlefs-with-ssl-on-esp32_dev-to-demo-wifi-scan)
     * [9.1 MRD/DRD => Open Config Portal](#91-mrddrd--open-config-portal)
     * [9.2 Config Data Saved => Connection to Blynk](#92-config-data-saved--connection-to-blynk)
+  * [10. ESP8266WM_MRD_Config using LITTLEFS with SSL on ESP8266_NODEMCU_ESP12E using new ESP8266 core v3.0.0](#10-esp8266wm_mrd_config-using-littlefs-with-ssl-on-esp8266_nodemcu_esp12e-using-new-esp8266-core-v300)
 * [Debug](#debug)
 * [Troubleshooting](#troubleshooting)
 * [Releases](#releases)